What is the difference between network adapters types?

Question

What is the difference between network adapters (NIC) types in virtual machine configuration?

Which network adapter is better for the virtual machine?

Answer

In virtual machine configuration you can choose between 4 types of network interface card (NIC):

Virtio network adapter is the fastest card. However, it works only in Linux and BSD guest operating systems. It is a default adapter for Linux-based OSes.

Intel® PRO/1000 MT is a default network adapter for Windows and Mac OS X virtual machines. It works in all operating systems. It also counts a checksum and splits packages. Thus it allows to increase the network performance.

Intel® Gigabit CT (82574L)
Support for this network interface was added in Parallels Desktop 11 for Mac. This is Intel's e1000e Ethernet driver.

Realtek RTL8029AS is the simplest adapter from the list. It does not count a checksum or split packages. The Realtek adapter can be used only if you have Parallels Tools installed in your virtual machine. Without Parallels Tools it will work very slow or even will not work at all. It works especially good with Windows XP virtual machines.